The track is called '18,' it's apparently a ballad and took Cowell "a millionth of a second to say yes" to the highly anticipated tune. Eek!

"He wrote a great song," Cowell revealed (quote via Sugarscape). "The funny story was that Ed came down to see me at 'Got Talent,' as he was performing, and he came up to the dressing room and I went, ‘Where’s the One Direction song?’ And he said ‘I didn’t know you wanted a song from me,’ and I went ‘Yeah.'"

“And then literally a week later he comes round to my house with his manager one night, turned up around 11 o’clock and said ‘Do you like this song?’ and he played me ‘18’ and it took me about a millionth of a second to say yes," Cowell continued about the track, which Sugarscape says is a ballad. "It’s turned out really well, Ed’s a real star and the fact that he did it in such a short space of time but he was so focused and he’s a brilliant songwriter."

"You know what I love about Ed?" he added. "He’s generous. He could have kept that song but he loves writing hits.”

And speaking of 1D hit-makers, Julian Bunetta (the co-writer behind 'Steal My Girl' and more) said that the band's upcoming album, 'Four,' is a "big One Direction musical rainbow."

“There is probably a whole bunch of stuff in between them ['Steal My Girl' and 'Fireproof'] that sound nothing like each other,” Bunetta told MTV. “So it’s just one big One Direction musical rainbow; one song is green and one song is blue, one song is red.”

And while 'Four' will boast writing credits from Sheeran and Bunetta, the band has definitely had a heavy hand in penning the tunes as well.

“I think most of [the songs] were written with the band, either with Louis and Liam or with Harry, and there is a couple of songs that the whole band wrote on at different stages,” Bunetta continued. “So there’s five different individuals in this group and they all have five different tastes, so naturally I think the music is going to be pretty diverse because of that.”